Pigment dyes



Patented May 24, 1932 UNITED, STATES PATENT OFFICE GEORG KRANZLEIN, CHRISTOPH HARTMAN N, AND ALBIN HARDT, FRANKFORT-ON- THE-MAIN-HOCHST, GERMANY, ASSIGNORS TO GENERAL ANILINE WORKS, INC., OF NEW YORK, N. Y., A CORPORATION OF DELAWARE PIGMENT DYES No Drawing. Application filed August 11, 1928, Serial No. 299,107, and in Germany September 11, 1926.

formula wherein R stands for a bivalent hydrocarbon radical and X for hydrogen or for one of the groups alkyl, aryl, amino, alkylimino or arylimino, substituted or not.

We have found that dyestufi's containing one or several acid groups, includin their water-soluble complex compounds with inorganic substances, as, for instance, soluble chromium compounds, copper compounds and alumina compounds (of. U. S. Patent specification No. 1,090,123 issued March 10, 1914, in the name of Ren Bohn and Karl Immerheiser, German patent specification No. 416,379 in the name of Gesellschaft fiir chemische Industrie in Basel and German patent specification 419,825 in the name of Badische Anilin- & Soda-Fabrik), can be converted into pigments in an excellent manner by adding to an aqueous solution of a salt of the dyestuffs in question an aqueous solution of a base or a salt thereof, which base has a basicity sufliciently great for the formation of a stable salt incapable of being hydrolyzed or capable of being hydrolyzed only with difliculty, and also renders the dyestulf insoluble or sparingly soluble in water.

As such basic organic materials have proved to be particularly useful cyclic bases of the following general formula:

wherein R stands for a bivalent hydrocarbon radical and X for hydrogen, alkyl or aryl, substituted or not, or for the amino group which may also be substituted, as, for instance: 2-methyl-benzimidazol of the 'formula:

HaC-NH b-nn H: N//

2-toluido-4.5-dihydroimidazol of the formula HaONH o-nrr-otrn-on,

or the like and substitution products thereof.

The same pigments can also be obtained dyestufl of the formula:

, OONB are dissolved in about. 2000 parts of water, and to this solution there is added at room temperature a solution of 50 parts of 2- ortho-toluido-benzimidazol of the formula:

in the calculated quantity of dilute hydrochloric acid. The yellow precipitate is filtered by suction and dried. It is an orangeyellow powder, soluble in concentrated sulfuric acid, in acetone and in benzyl alcohol to a reddish-yellow, in alcohol and benzene to a yellow solution.

In the preceding example the azo dyestufi may advantageously be replaced by the combination ortho-anihne-sulfonic acid coupled with l-ortho sulfophenyl 5 pyrazolone-3- carboxylic acid or para-anilinesulfonic acid can led with 1.2-chloro-5'-sulfophenyl-3- met yl-5-pyrazolone. f

(2) To an aqueous solution of 20 parts of the dyestufi of the formula:

COONB there is added at about 10 C. to 20 C. a solution of 10 parts of 2-methylbenzimidazol of the formula NH \LOHI (about two molecular proportions) in the calculated quantity of dilute hydrochloric acid. The resulting precipitate is filtered and dried. It is a dark violet powder, almost insoluble in water, soluble in alcohol to a reddish-violet and in benzyl alcohol to a bluish-violet solution. The color of its solution in concentrated sulfuric acid is yellowish-red which on addition of formaldehyde gradually turns to bluish-red.

(3) 10 parts of the dyestufi SOaNa are precipitated in an aqueous solution at room temperature with a neutral solution of 6.5 parts of 2-hexahydroanilino-4.5-dihydroimidazol of the formula:

H: N// l l in the calculated quantity of dilute hydrochloric acid. The precipitate is filtered by suction and dried. It is a red powder, dissolvmg to red solutions in alcohol, acetone, butanol, benzyl alcohol and pyrantone, fur thermore in alcohol lacquers, cellulose-ester and -ether lacquers, and nitrocellulose lacquers.

(4) 10 parts of the dyestufi:

. SOzNa are precipitated in an aqueous solution at room temperature with a neutral solution of 8 parts of Q-anilino-benzimidazol of the formula: 1

(5) 10 parts of the dyestufl' CcH|N=N N= N SOINB SOzNB SO|Na are precipitated in an aqueous solution with a warm solution of 12 parts of 2-anilidoperimidine of the formula:

in water and the calculated quantity of hydrochloric acid. The resulting compound when separated and dried constitutes a red powder of about the same solubility as the dyestufi' obtainable according to the preceding example.

For the anilido erimidine used in this example there may e substituted similar compounds, as, for instance, 2-amino-perimidine of the formula:

.(6) 17 parts of sodiuml-aminoA-phenyl- ,aminoanthraquinone-2-su1fonate are precipitated in the manner above indicated with a neutral solution of 7 parts of 2-toluido-4.5- dihydroimidazol in dilute hydrochloric acid. The dried precipitate is a blue powder show- 5 ing the same properties of solubility as the dyestufi prepared in Example 4.

(7) A neutral solution of 17 parts of 2- toluido-i.5-dihydroimidazol in dilute hydro- I chloric acid is run, while stirring, into an 10 aqueous solution of 60 parts of the chromium complex salt of 2.4-naphtholsulfonic acid-1- azo nitrophenyl -methylpyrazolone'- sulfamide. The red precipitate is filtered by suction, dried at 50 C. to 60 C. and very finely ground. The red powder readily dissolves in methyl alcohol, rather diflicultly in alcohol, and it is soluble in alcohol lacquers, celluloseester and -ether lacquers, and nitrocellulose lacquers, insoluble in benzine, benzene and benzylacetate.

Instead of thed estufis named in the preceding examples t ere may be used for producing the pigment dyes in like manner other dyestuffs of the most various classes of dyestuffs, provided only that they contain acid salt-forming groups, as, for instance, 1-amino-4- ara acetaminoanilido 2 anthraquinonesul onic acid of the formula I NH:

SOINa 36 NH. CSHLNH. 00.011:

1.41- dihydroxy- 5.8 di para toluidoanthraquinonedisulfonic acid, 1.5-dihydroxy-4.8--

methylanthrapyridonet-arylsulfonic acids of the formula t Eli/k1. CH:

1.4- diaminoanthraquinone-2-phenoxysulfonic acid of the formula:

ONH:

NaOzS NH. CO-NH -8 OaNl n n or the dyestufl of the formula:

NaOzS N=N.CHl

or rhodamines or triphenylmethane dyestuffs, as for example the acid triphenylmethane dyestufi' of the formula:

N y mot mc f om can Hons 0310a or the dyestuif of the following formula:

H10. 11.0.. HN GM 0-H; CH:

AOINB (I ky OOONa obtainable by the action of ortho-toluidine .upon fluorescei'n chloride and sulfonation of the reaction product, and other dyestuffs.

For preparing water-insoluble or sparingly-soluble precipitates, the organic bases used as precipitating agents for each of the dyestuffs indicated may also be used in any desired combination to any of the other-enumerated dyestufis and generally to all dyestuffs containing acid salt-forming groups.

The receding examples form only a small part 0 the pigments obtainable by suitably selecting the bases and dyestuffs. They are particularly useful and of strong coloring power, and they yield tints of good fastness to light. V

III

The said pi ent dyes are insoluble or difiicultly solu 1e in water, but soluble in many organic solvents, some of them being otherwise known as solvents for cellulose esters or cellulose others and for lacquers. Therefore said pigment dyes are useful in dyeing solutions of cellulose ethers and cellulose esters and of lacquers in organic solvents.

chanically mixed in a dry way with one of the usual substrate), as, for instance, hydrate of alumina, heavy spar, blanc fixe, or a mixture thereof, may be mixed with varnish and printed, or mixed with linseed oil and applied with a brush, or mixed with an aqueous binding agent and applied with a brush, or

the pigments are mixed. in the form of an aqueous paste with the dry or water-moist usual substrata, for example those above indicated, dried and mixed with varnish as above described; they yield very intense clear shades of ver good fastness to light.

The precipitation of the dyestufi salts with the salts of the or ic bases or the reaction of the free dyestu acids with the free bases can, of course, also be effected in the presence of a substratum, as, for instance, of one of those above indicated, hydrate ofalumina,

so heavy spar, blanc fixe or a mixture thereof.

We claim:

1. As a new product, the salt formed from the chromium complex salt of 2.4-naphtholsulfonic acid 1 azo -nitro phenyl methylpyrazolone-sulfamide and from 2-toluido- 4.5-dihydro-imidazol being a red powder, soluble in alcohol, methyl glycol, alcohol lacquers, cellulose-ester and -ether lacquers,

4 and nitrocellulose lacquers and yielding a clear tint of great fastness to li ht.

2. As new roducts, the salts ormed on the one side om an organic dyestufi containing at least one acid salt-forming group 4 and on the other side from a cyclic-organic 5 base of the general formula:

The pigments as such or after being mecellulose lacquers.

on the other side from a cyclic organic base of the general formula: NH n b-x f wherein R stands for a bivalent hydrocarbon radical of the grou consisting of ethylene, phenylene and napthylene, and X stands for a substituent of the oupconsisting of hydrogen, methyl, ammo, methylimmo, phenylimino, tolylimino and cyc ohexylimino, the said salts being insoluble or difficultly soluble in water, but 'soluble in alcohol, acetone, benzyl alcohol, butanol, cyclohexanone or cyclohexanol. 4. As new roducts, the salts formed on the one side em an organic dyestufi containing at least one acid salt-forming group and on the other side from a 4.5-dihydroimidazol-compound of the following general formula:

wherein X represents a radical of the rou consisting of phenyl, tolyl and cyclo exyl the said salts bein insoluble or diflicultl soluble in water, ut soluble in alcoho, acetone benzyl alcohol, butanol, cyclohexanone or cyclohexanol.

5. As new products, the salts formed on the one side from an azo dyestufi containing at least one acid salt-forming group and on the other side from a 4.5-dihydroimidazol compound of the following generalformula:

and from 2-hexahydroanilino-4.5-dihydroimidazol, being a red powder, soluble 1n alcohol, acetone, butanol, benzyl alcohol, pyrantone, furthermore in alcohol lacquers, cellulose-ester and -ether lacquers and nitro- In testimony whereof, we aflix our signatures.

GEORG KRANZLEIN. CHRISTOPH HARTMANN ALBIN HARDT. 

